J/MNRAS/495/1807    Stellar populations in LAEs and LBGs   (Arrabal Haro+, 2020)
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Differences and similarities of stellar populations in LAEs and LBGs at
z~3.4-6.8.
    Arrabal Haro P., Rodriguez Espinosa J.M., Munoz-Tunon C., Sobral D.,
    Lumbreras-Calle A., Boquien M., Hernan-Caballero A., Rodriguez-Munoz L.,
    Alcalde Pampliega B.
   <Mon. Not. R. Astron. Soc., 495, 1807-1824 (2020)>
   =2020MNRAS.495.1807A    (SIMBAD/NED BibCode)
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ADC_Keywords: Galaxies ; Redshifts ; Populations, stellar ; Stars, ages ;
              Models ; Optical ; Infrared
Keywords: galaxies: evolution - galaxies: high-redshift -
          galaxies: luminosity function, mass function -
          cosmology: observations - dark ages, reionization, first stars

Abstract:
    Lyman alpha emitters (LAEs) and Lyman break galaxies (LBGs) represent
    the most common groups of star-forming galaxies at high z, and the
    differences between their inherent stellar populations (SPs) are a key
    factor in understanding early galaxy formation and evolution. We have
    run a set of SP burst-like models for a sample of 1558 sources at
    3.4<z<6.8 from the Survey for High-z Absorption Red and Dead Sources
    (SHARDS) over the GOODS-N field. This work focuses on the differences
    between the three different observational subfamilies of our sample:
    LAE-LBGs, no-Ly{alpha} LBGs, and pure LAEs. Single and double SP
    synthetic spectra were used to model the spectral energy
    distributions, adopting a Bayesian information criterion to analyze
    under which situations a second SP is required. We find that the
    sources are well modelled using a single SP in ~79 per cent of the
    cases. The best models suggest that pure LAEs are typically young
    low-mass galaxies (t~26^+41^_-25_Myr;
    M_star_~5.6^+12.0^_-5.5_x10^8^M_{sun}_), undergoing one of their first
    bursts of star formation. On the other hand, no-Ly{alpha} LBGs require
    older SPs (t~71+/-12Myr), and they are substantially more massive
    (M_star_~3.5+/-1.1x10^9^M_{sun}_). LAE-LBGs appear as the subgroup
    that more frequently needs the addition of a second SP, representing
    an old and massive galaxy caught in a strong recent star-forming
    episode. The relative number of sources found from each subfamily at
    each z supports an evolutionary scenario from pure LAEs and single SP
    LAE-LBGs to more massive LBGs. Stellar mass functions are also
    derived, finding an increase of M_*_ with cosmic time and a possible
    steepening of the low-mass slope from z~6 to z~5 with no significant
    change to z~4. Additionally, we have derived the SFR-M_star_ relation,
    finding an SFR{prop.to}M_star_^{beta}^ behaviour with negligible
    evolution from z~4 to z~6.

Description:
    Arrabal Haro et al. (2018MNRAS.478.3740A, Cat. J/MNRAS/478/3740) used
    the 25 medium-width filters (full width at half-maximum~17nm) of the
    SHARDS ESO/Gran Telescopio Canarias (GTC) survey (Perez-Gonzalez et
    al. 2013ApJ...762...46P, Cat. J/ApJ/762/46) to simultaneously select
    LAEs and LBGs. The sample of high-z galaxies was selected via colour
    excesses and photometric fits of their SEDs.

    The final sample consists of 1558 sources at z~3.4-6.8, distributed
    into 1434 LBGs (404 of them showing Ly{alpha} emission line with
    EW_0_>5.1{AA}), and 124 pure LAEs (m_1500_>~27.0AB; Ly{alpha}
    EW_0_>35{AA}). In order to further extend our SEDs beyond the SHARDS
    wavelength range, we also use ancillary broad-band GOODS-N data from
    HST/ACS (Giavalisco et al. 2004ApJ...600L..93G, Cat. II/261; Riess et
    al. 2007ApJ...659...98R), HST/WFC3 (Grogin et al. 2011ApJS..197...35G;
    Koekemoer et al. 2011ApJS..197...36K), and Spitzer/IRAC (Fazio et al.
    2004ApJS..154...39F; Perez-Gonzalez et al. 2005ApJ...630...82P,
    2008ApJ...675..234P, Cat. J/ApJ/675/234; Ashby et al.
    2015ApJS..218...33A, Cat. J/ApJS/218/33), as available in the Rainbow
    Cosmological Surveys Database (Barro et al. 2011ApJS..193...13B, Cat.
    J/ApJS/193/13, 2011ApJS..193...30B, Cat. J/ApJS/193/30,
    2019ApJS..243...22B).

    Single and double stellar population (SP) models are used to fit every
    SED, using a Bayesian Information Criterion (BIC) calibration to
    decide in which situations an extra SP is needed. In Table 2, we
    present the IDs, coordinates, ages, and stellar masses derived for our
    1555 well-modelled galaxies.

File Summary:
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 FileName      Lrecl  Records   Explanations
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ReadMe            80        .   This file
table2.dat       101     1555   Main physical parameters derived from the best
                                models fitted to each source
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See also:
  J/MNRAS/478/3740 : High-z LAEs and LBGs in SHARDS survey (Arrabal Haro+, 2018)
  J/ApJ/762/46     : SHARDS: GOODS-N spectrophotometry survey
                                                         (Perez-Gonzalez+, 2013)
  II/261           : GOODS initial results (Giavalisco+, 2004)
  J/ApJ/675/234    : Stellar mass functions for galaxies 0<z<4
                                                         (Perez-Gonzalez+, 2008)
  J/ApJS/218/33    : Spitzer-CANDELS catalog within 5 deep fields (Ashby+, 2015)
  J/ApJS/193/13    : Spitzer/IRAC sources in the EGS I. SEDs (Barro+, 2011)
  J/ApJS/193/30    : UV-to-FIR analysis of sources in the EGS. II.
                                                                  (Barro+, 2011)

Byte-by-byte Description of file: table2.dat
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   Bytes Format Units      Label   Explanations
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  1-  14 A14    ---        Name    Source name (SHARDSNNNNNNNN)
 16-  17 I2     h          RAh     Right ascension (J2000)
 19-  20 I2     min        RAm     Right ascension (J2000)
 22-  25 F4.1   s          RAs     Right ascension (J2000)
      27 A1     ---        DE-     Declination sign (J2000)
 28-  29 I2     deg        DEd     Declination (J2000)
 31-  32 I2     arcmin     DEm     Declination (J2000)
 34-  37 F4.1   arcsec     DEs     Declination (J2000)
 39-  42 F4.2   ---        z       Redshift
 44-  47 F4.2   ---      e_z       Error on z
 49-  53 F5.1   10+9Msun   Mstarm  Main stellar population mass
 55-  59 F5.1   10+9Msun e_Mstarm  Error on Mstarm
 61-  64 I4     Myr        Agem    Main stellar population age
 66-  68 I3     Myr      e_Agem    Error on Agem
 70-  72 F3.1   Myr        tau0    Main stellar population e-folding time
                                    stellar populations
 74-  76 F3.1   Myr      e_tau0    Error on tau0
 78-  81 F4.1   10+9Msun   Mstarb  ? Burst stellar mass (1)
 83-  86 F4.1   10+9Msun e_Mstarb  ? Error on Mstarb
 88-  89 I2     Myr        Ageb    ? Burst age (1)
 91-  92 I2     Myr      e_Ageb    ? Error on Ageb
 94-  97 F4.1   Myr        tau1    ? Burst e-folding time (1)
 99- 101 F3.1   Myr      e_tau1    ? Error on tau1
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Note (1): If no double stellar population (DSP) model was required, these
          columns are left empty
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History:
    From electronic version of the journal

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(End)                                           Ana Fiallos [CDS]    13-Jun-2023